Optimal Antiplatelet Treatment to Achieve Stroke Avoidance and Fall in Bleeding Events following Left Atrial Appendage Closure – Chronic Kidney Disease (SAFE LAAC CKD). Comparative Health Effectiveness Ancillary Study – PILOT

Prior treatment

• Any indication to chronic antiplatelet therapy other than atrial fibrillation or left atrial appendage occlusion. 2. Indications to chronic anticoagulation 3. Known allergy to clopidogrel of acetylsalicylic acid 4. Diagnosis of coagulation disorders 5. Peridevice leaks greater than 5mm 6. Thrombus in the left atrium on the qualifying imaging of the left atrium 7. Life expectancy less than the duration of the trial due to noncardiovascular comorbidity 8. Enrollment into a competing trial using a non-approved devices or drugs - currently and up to 3 months prior to enrolment 9. Women who are pregnant or breastfeeding and those women of childbearing potential who do not agree to use at least two contraceptive measures (oral contraception, mechanical contraception, approved contraceptive implants, intrauterine device, tubal ligation). The criterion does not apply to women who have been postmenopausal for at least 2 years prior to study enrollment (defined as at least one year without menstrual periods) or underwent surgical sterilization procedure. All eligible women who are younger than 55 years must have negative pregnancy test within 24 hours prior to randomization.

• Successful percutaneous left atrial appendage occlusion with Amplatzer or WATCHMAN devices within 37 days prior to randomization 2. End-stage renal disease treated with chronic hemodialysis or chronic peritoneal dialysis 3. Age >= 18 yrs 4. Participant is willing to comply with all aspects of the protocol including the assigned treatment strategy and follow-up visits 5. The participant is willing to give written informed consent